Despite its importance at critical junctures in families' lives, little is known from nationally representative datasets about grandparent- grandchild coresidence. This project aims to systematically describe and model coresidence between grandparents and grandchildren, using data from the 1987 and 1992 waves of the National Survey of Families and Households (NSFH). The specific aims are of four types: first, having recoded and reorganized the data, to use the Wave 1 data to estimate the prevalence of grandparent-grandchild coresidence in the United States overall and in subgroup; second, to model flows of goods and services within grandparent-grandchild homes; third, to link Wave 1 and Wave 2 and estimate the probability that a grandparent-grandchild coresidence ended or that a coresidence began between Wave 1 and Wave 2; and fourth, to explore theoretical multivariate models of grandparent-grandchild and of the processes that cause grandparent-grandchild coresidence to begin or to dissolve over time. Early work on the project identifies 8.8 percent of households with children as including a grandparent. This rate is almost tripled (24 percent) among single parents and quadrupled (35 percent) for parents under age 20. As many scholars have pointed out, intergenerational bonds remain strong in the United States, sustained through visits, gifts, phone calls and, at times, practical help. Nevertheless, most grandparents do not live with their grandchildren. When they do, it is often a marker of family stress or transition. For example, it may follow divorce, widowhood or early childbearing, or families may face chronic problems that make it hard for one or the other to live independently. Or it may be because the family's cultural traditions encourage, even require, grandparent coresidence. Many of the factors that make grandparent coresidence more likely-single parenthood or extreme parental inadequacy (due e.g. to drug addiction) among the younger generation, survival to an advanced age and associated need for services among the older generation, economic difficulties (such as high housing costs accompanied by low family income) at any age, as well as growing ethnic diversity in the United States-have become increasingly common in the past two decades. At the same time, the number of children living in their grandparents' homes has increased, from 3.2 percent of children in the 1970 Census to 4.9 percent in the 1990 Census and 5.6 percent in the 1995 CPS. Because these counts omit grandparent-grandchild coresidence that occurs when grandparents live in the homes of their adult children, they are not national estimates of grandparent-grandchild coresidence. They do, however, indicate the increasing prevalence and importance of the phenomenon.